Wayne Rooney injury could be a blessing in disguise for United

On Wednesday morning, Manchester United fans would have said their season couldn't have got much worse.

With home and away victories over Liverpool aside, supporters have had little to celebrate following early exits from the Champions League and League Cup, and failure to stand a reasonable chance of finishing in the top four in the Premier League.

Earlier in the season, fans were regularly calling for Wayne Rooney to be dropped from the starting team and Anthony Martial to be played up front with Juan Mata or Ander Herrera playing behind him.

However, since the turn of the year, Rooney has discovered some good form, scoring seven goals in nine games. Then came the news from Louis van Gaal on Wednesday that Rooney has sustained a knee injury, which will probably keep him out of the team for at least the next six weeks.

An optimistic view would see him return for United's home game against Everton at the beginning of April, while other reports would suggest he will only be present for United's final few games of the season, missing the matches against Arsenal, Manchester City, Everton and Tottenham.

While plenty of fans may criticise the decision now, when David Moyes convinced Rooney to sign an extension deal with the club two years ago, it was hailed as a success for the new manager.

Moyes' reign can largely be dismissed as a massive failure, but talking Rooney into snubbing Jose Mourinho's advances and staying put was certainly a positive move for the club at the time. Sir Alex Ferguson had previously paved the way for Rooney's exit, claiming the striker had asked to leave in the manager's last home game in charge against Swansea, but Moyes was able to rectify the situation.

Wayne Rooney, who was finding his form for Man United, is now set to be sidelined for approximately two months.

In hindsight, the decision to keep him as the club's highest earner was a poor one, with Ferguson correctly identifying the player was past his best. He may well have gone on to enjoy a successful season for Chelsea in 2013-14 had he been allowed to leave, possibly firing them to the title, and that would have been used as a stick to beat Moyes with. But to see Rooney sign up until 2019, a couple of months short of his 34th birthday, was a crazy move.

Jamie Carragher recently claimed that we should already view the United captain as a 35-year-old, given the number of games he has under his belt, so he may well be as knackered as a 40-year-old when his current contract expires.

Since the extension, Rooney has scored 36 goals in 81 games, an average of 0.4 goals per game, which is nothing like the return you would expect from the top earner at the third richest club in the world.

When comparing him to the strikers of rival Premier League teams, who earn less, Rooney doesn't come off very well. Sergio Aguero has averaged 0.74 goals per game over the past two seasons, Harry Kane 0.58 goals per games, and Oliver Giroud 0.56 goals per game.

Even Rooney at his peak, scoring 34 goals 2011-12 and in 2009-10, still was vulnerable to going long periods without scoring regularly. Now, with his best days behind him, those sparse periods have lasted longer and with fewer goals.

However, Rooney's upturn in form over recent weeks gave some hope to the fan base. Before the turn of the year, he had seven goals from 23 games, with three of those coming from a hat trick in United's Champions League qualifying games against Club Brugge. His seven goals from nine matches in 2016 (0.8 goals per game) suggest he may now be missed more now than he would have been a few months ago.

United haven't been free scoring, but it would be fair to argue that if they had Aguero, Kane or Alexis Sanchez up front, they'd have scored more than they have with Rooney leading the line.

Still, their chances of finishing top four were fairly slim even when he was playing up front and scoring fairly regularly. Their chances have certainly diminished without him. However, if Herrera and Mata manage to link up as well as they did during the club's purple patch in March of last year, now with Martial leading the line, who knows what might happen?

And, as a silver lining, at least Rooney's chances of replacing Sir Bobby Charlton as the club's highest scorer have diminished. Rooney has reportedly been keen to leave United for both City and Chelsea in recent years, so maybe it's a blessing in disguise if he misses the rest of the season and leaves for Everton or China in the summer, still short of Sir Bobby's 249 goals.

In all honesty, his presence would have probably added little to United's chances of success this season, but his goals could have seen a man who is red through and through replaced by an Everton fan who isn't too bothered about which Premier League club pays him a salary.

United will miss Rooney over the next few months, particularly his fighting spirit in the big games, but his injury is a fair reflection of his season as a whole. He hasn't been good enough and his absence probably won't have the impact that you would expect for a team without their captain, if the example of Vincent Kompany at Manchester City is anything to go by.

Scott is one of ESPN FC's Manchester United bloggers. Follow him on Twitter: @R_o_M.